Sheets-xsheet i



NOV. 18, v H, HAY T 2,618,693

IGNITION SWITCH C(INTROLLED SAFETY DEVICE Filed Aug. 3, 1951 2 SPEETS-SI-IEET 1 Fig.1

as 20 z 2 Vernon H. H ya/f J. Armfieia q INVENTOR'i Nov.- 18, 1952 v. H. HAY ETAL 2,618,693

IGNITION SWITCH CONTROLLED SAFETY DEVICE Filed Aug. 5, 1951 2 SHEETS-SHEET 2 Vernon H. Hay Wyaff J- Armfie/a INVENTORiZ Patented Nov. 18, 1952 IGNITION SWITCH CO DEVIC NTROLLED SAFETY Vernon H. Hay and Wyatt J. Armfield, Concord, N. 0.

Application August 3, 1951, Serial No. 240,260

2 Claims. 1

This invention relates to electrical safety switches and more particularly to safety switches for automobiles, airplanes, and other self-propelled vehicles and it has for a general object to provide a switch of the type generally termed a master switch, controlling all the connections with current consuming units of an automobile or other self-propelled vehicle with a source of current which is automaticall operable upon operation of the ignition switch and which may be locked in the position adopted without any current consumption during the time in which the said master switch remains locked.

A further object of the invention consists in providing locking means for locking the switch in one of its positions without current consumption and in such a manner that the lock may be released by the operation of the ignition switch.

Further and more specific objects will be stated below in detail.

Master safety switches for automobiles, airplanes and other vehicles cuttin off all connections between the source of current and all or any of the circuits of the vehicles to reduce fire hazard are well known in the art. They are usually operated by hand or they may be operated automatically under certain conditions occurring during the operation of the vehicle or during accidents, for instance by gravity, deceleration or the like. Further it is known to operate such a master switch indirectly by operation of the ignition switch, the master switch being turned on when the ignition switch is turned on and being turned off when the ignition switch is turned off. This connection may either be a mechanical or an electrical connection. A mechanical connection between the ignition switch and the master switch has the advantage that it does not entail current consumption, but it is always difiicult to produce and unreliable to a certain extent, as the ignition switch must be located on the dashboard of the veihicle and the master switch should be arranged :as closely as possible to the battery. If so located a long connection which is far from being straight and which therefore has much friction is necessary which connection entails the application of some force and is not fully reliable and positive in its action on account of the imperfect mechanical connection. It is also rarely fully locked against accidental operation. An electrical connection between the ignition switch and the master switch is therefore preferable, but it is always current consumin also during the periods of rest, as the switch must be locked. Either the switch itself or a locking device must be supplied with electrical energy to maintain the master switch in its locked position.

According to the invention the connection between the ignition switch and the master switch is electrical, but the master switch comprises not only a switching device but also a locking device cooperating in such manner with the switching device and so interlocked with it that the locking operation of the master switch is performed by mechanical means which are controlled by a locking solenoid. The latter however becomes automatically de-energized with the locking device, remaining operative as long as the master switch has adopted its desired position. For unlocking it is necessary to energize the locking device which then unlocks the switching device, but also turns it off, this turning off of the switching device also de-energizing the locking device and locking it mechanically.

It will thus be seen that the master switch and its switching and locking devices draw only current while one of them is engaged or disengaged while no current is drawn permanently. On the other hand both devices are safely locked in their position and cannot adopt any position other than that prescribed, as is frequently the case with mechanically operated locking means which are moved accidentally to an intermediate position or which get stuck in such a position.

The invention has been described with reference to the accompanying drawings showing one embodiment thereof. It is however to be understood that the embodiment shown in the drawing by way of example has been selected in order to explain the principle of the invention and the best mode of applying said principle. A modification of the example shown may obviously be made without departing from the principle of the invention and therefore such modifications are not necessarily a deviation from the essence of the invention.

In the drawing:

Figure 1 is a diagrammatic Sectional and elevational view of a master switch according to the invention, the figure showing the devices in their locked position;

Figure 2 is a similar view showing the master switch in another position;

Figure 3 is an end view of the switching device and of the adjoinin part of the locking dev1ce;

Figure 4 is a sectional plan view, the section being taken along line 4-4 of Figure 2 Figure is an elevational side view the section being taken along line 55 of Figure 2.

The safety switch is shown in the drawings in two characteristic positions. In the drawing it indicates the ignition switch which in this case is so constructed that it may adopt three different positions. In the first position or off position both the ignition switch and the master switch are turned oil. In the second position the ignition switch is turned oii, while the master switch is on. In this position the key can be removed so that the circuits of the parking lights or of other lights remain on and merely the ignition is turned off. In a third position of the ignition switch both the ignition switch and the master switch are turned on.

These positions are merely diagrammatically indicated in the drawing the three positions of the ignition switch being marked l, 2, 3, while the contacts of the ignition switch with the connections leading to the master switch device are indicated at H and i2.

The master switch as seen in Figures 1 and 2 comprises a main switching device I5 which includes a solenoid H5 operating a plunger ll which consists of a solenoid core 58 and a contact sup porting plunger rod 19. The plunger rod of the switching device is equipped with contacts capable of carrying heavy ciurents. This contact device preferably consists of a loosely mounted annular disk 28 which may be provided with a central insulating ring 23 and which is held between insulating washers 2! and pressed against a further or intermediate disk 22 by means or a coil spring 2 The disk 22 in its turn is under pressure of a further coil spring which is supported on a plate 2'5 fixedly mounted in the casing 21 surrounding the entire switching device 15. The coil spring 24 is held by a retainer disk 28 fixedly held on the plunger rod 19.

The contact 25] is thus held between springs 25 and 25 and therefore is always pressed against the fixed contacts under heavy elastic pressure, whatever the position to which the rod i9 and the core [8 is moved.

The plunger rod is passes to the outside through a suitable opening in the casing 2? surrounded by a guide piece as which guides the said rod. The outward movement of the plunger rod may either be allowed or may be prevented by a lockingmeans as described below.

The fixed contacts of the switching device i5 are formed by the bolts 3t, 31, 32, 33 of terminal screws which are mounted on the casing 27 and are insulated therefrom by insulated washers. The bolts partly project into the casing and are so arranged that bolts 33, 3| and the bolts 52, 33 will come into contact with the contact disk 29 simultaneously in each position of the disk, good contact with both bolt ends being maintained by the springs.

The contact terminal 30 is connected with a grounded battery 35, while the second contact terminal 3| cooperating with it, is connected with a conductor 36 leading to the ignition switch it over the locking solenoid to be described below.

It will be clear that in the position of the plunger l7, shown in Figure 1, the contacts 3B, 31 are bridged by the annular disk 26 so that the conductor 36 is under current. The contact terminal 32 which is connected with the contact terminal 33 by the disk when the plunger ll moves down, is grounded at 3'! for a purpose described below, while contact terminal 33 is connected with contact terminal 3,! of the second set of contacts by means of conductor 38. The contact terminal 33 is moreover connected with a load circuit 49, as indicated in Figures 1 and 2. Therefore, when the disk 20 is in its operative position the load circuit is connected with the battery or source of current 35 over the contacts 28 and iii, the lead 38 and the terminal 33. The load circuit, on the other hand, and especially the generator circuit, is however grounded at 3'! when the contact disk 20 is in its position of rest or inoperative position. This prevents the burning out of lights when the motor and generator is still running at high speed while the switch is thrown.

It will be clear that the plunger rod i5 is normally moved outwardly by the tension of the springs 24, 25. It is pulled inwardly by the solenoid it acting on the core 18 which is energized by means of the terminal 4! mounted in the casing 27 and connected with conductor 32. The other side of the solenoid winding is connected by means of a connecting wire 5% with the contact terminal 30 which, as above de-- scribed, is joined to the battery 35. Obviously when the solenoid I5 is energized the plunger rod i9 is moved inwardly against the tension of the springs 24 and 25.

The locking device d5 of the master switch comprises a casing housing a solenoid 58 which operates a plunger 58. The plunger consists of a core member 5! and a plunger rod 52. The solenoid is connected with two terminals 53, 5:2 which are mounted in the casing d6 but are insulated therefrom. These terminals are connected with conductors 35 and 66 respectively, which lead to terminals 3! and 33 of the switching device and to the ignition switch respectively. The plunger rod 52 carries two fixed disks 55, 56, the former being under the tension of spring 5? moving the plunger rod outwardly. An annular disk 6% which may carry an insulating ring 65 in the center, is inserted between the two fixed disks 55, 55 and is pressed towards the former by a spring 58 which, at its other end, is pressed against the disk 55. On both ends of the contact disk E55 insulating washers may be arranged to prevent contact of the disk with other metallic parts.

The disk cooperates with the two contacts t3, 6% formed by contact bolts passing through the casing do, but insulated therefrom. The bolts are held by suitable nuts and are provided with further nuts for clamping the wires attached to them. The outwardly projecting ends of the bolts 63, 5d form terminals which are connected with conductors and d2 respectively leading to the ignition switch and to the terminal ii of the switching device, respectively.

The plunger rod passes through an opening in the casing it to the outside and may be guided during its passage through said opening by a guide piece 6'! attached to the casing. The plunger rod 52 is provided with a forked end carrying a pivot connection 58 at which the looking plate 59 is pivoted to the rod. The locking plate {55 may be moved over a second perforated plate it which is provided with a circular bore or hole ii, the latter being located in the path of the plunger rod [9 of the main switching device it. The perforated plate 73 is so arranged that the axis of the plunger rod 59 coincides with the axis of the circular hole or bore ii.

The locking plate as is so positioned that it covers the hole ll when the plunger rod 52 has ceen moved outwardly, so that the head ii? of the plunger rod [9 comes to rest on said locking plate 59 and is held in a position in which plunger rod is withdrawn to the largest possible extent. Thus, the plunger rod I8 is prevented from moving outwardly as long as the locking plate 59 covers the opening 7; and forms a rest for the head 69 of the plunger rod. When the locking plate 8% is withdrawn however, the plunger rod It may freely move through the hole or bore H until the disk 28 comes to rest against the contacts 32, 33.

The operation of the device will be readily understood from the above description. Let it be assumed that the plunger rod 52 has been withdrawn inwardly and therefore has also withdrawn the locking plate inwardly, so that the opening H is now uncovered and the plunger rod l9 may therefore pass through this opening. The contact disk of device !5 in this case rests on the two contacts 32, 33 and the contact disk iii! of the locking device rests on the contacts 68, dd. This position is shown in Figure 2. All the circuits are now grounded including the circuit 65, 36 of solenoid it and the load circuit 4%. The battery is disconnected from the load circuits. It will be observed that the springs 51 of locking device 45 would in this case tend to move the plunger rod 52 and the locking plate 89 outwardly, but the plunger rod in this case is prevented from moving in this direction, because the locking plate 69 abuts against plunger rod I9 thus preventing this movement.

Let it be further assumed that now the master switch is to be thrown into its operative or on position, because the car and its circuits have to be operated. The ignition switch in this case is moved from its first or inoperative position into its second position in which it makes contact with contact H, a current now passes from ground 9 to switch it, contact H, conductor 65, contacts 53, contact disk 59, contact t l, conductor 42, terminal M to the winding of solenoid It and through conductor M to terminal 3i! connected with battery 35. The solenoid I6 is thus energized and attracts its core it and therefore retracts plunger rod 19 connected with the core.

The disk 28 now comes into contact with the two contact members 3d, and connects the battery 35 with the load circuit it over the contact terminal 3! which, as above mentioned, is now connected with contact 3i! through disk 25] and to the battery 35 by means of conductor 33 leading to contact terminal 33. The springs 24 and 25 are compressed and the plunger rod i9 has been withdrawn by the solenoid into the interior thus permitting again a movement of the locking plate 69 under the action of springs 53, 5! pressing on rod The outward movement of locking plate 69 covers the opening ii in the perforated plate Ell therefore locks the plunger rod it in its position. The car is now in operative condition and remains in such condition also if the ignition switch in is returned to its normal position indicated at it. Upon moving the ignition switch into its normal position the current through winding of the solenoid I6 is interrupted but the switching device 25 remains in its position as it is locked by the locking plate 69. The device does not consume power during operation as the solenoid 43 has been cut out and the circuit of solenoid it is interrupted at contacts 63, Ii -i.

If it is desired to throw the master switch into its inoperative or off position the ignition switch Ill is moved from its normal position indicated at M towards contact l2. A current then flows through solenoid 48 from ground 9 over ignition switch [0, contact l2, conductor 66, solenoid winding 48, terminal 53, conductor 36, contact terminal 3 I, contact disk 20, contact member 3!], battery 35 to ground H30. The winding of the solenoid 48 attracts the core 5i and therefore moves plunger rod 52 inwardly, withdrawing the support from head 49 of plunger rod Id. The hole H in the perforated plate 10 is therefore again uncovered and the plunger rod [9 under the action of springs 24, 25 moves outwardly; the disk 20 now contacts the contact members 32, and 33 and breaks contact with contact members 30, 3!.

This grounds the conductor 38 so that the plunger 50 is no longer attracted by the solenoid but the plunger rod 52 cannot move outwardly under the action of springs 51, 58 because the locking plate 69 is held by the plunger rod It. The situation shown in Figure 2 of the drawing is therefore restored. The load circuits are all grounded and current is cut off from winding 43 by its connection with ground 31.

It will thus be seen that the above invention provides a safety switch which is operable by the ignition switch by electrical means and which may be locked in its position without requiring electrical energy for maintaining the switch in its locking position.

It will also be understood that the foregoing description introduces a number of specific details which are not indispensable for carrying the principle of the invention into effect and therefore a change in these unessential details does not constitute a departure from the essence of the invention as defined in the annexed claims.

Having described the invention, what is claimed as new is:

1. A safety device controlling the connection between a source of current and the depending current excited elements of a system, said system including a manually operated control switch, said safety device comprising a solenoid operated switching device including a solenoid, a plunger provided with a solenoid core operated by said solenoid, and with a plunger rod attached to said core, spring means moving said plunger rod in a direction opposed to the direction of movement of the core upon energization of the solenoid, a first pair of contacts connected with said source of current and with the elements of the system and a solenoid operated locking device respectively, a movable contact carried and operated by said plunger rod connecting said first pair of contacts when the solenoid is energized, a second pair of contacts connected to ground and to said solenoid operated locking device and said elements of said system respectively, means continuously urging said movable contact to engage said second pair of contacts, a solenoid operated locking device having a solenoid and being arranged adjacent to the switching device and provided with a plunger rod substantially at right angles to the plunger rod of the switching device and a movable contact carried and operated by said plunger rod of the locking device, and with spring means for moving the plunger rod of the locking device in one direction, the said locking device being further provided with a locking plate attached to said plunger rod of the locking device and adapted to be moved into the path of the plunger rod of the switching device for locking the same into its operative position, energizing circuits for each of said solenoid operated devices interlocking the operation of said devices so as to automatically look when brought into operative position, said energizing circuits including one pair of contacts connected to said solenoid operated switching device and to one terminal of said manually operated switch, respectively, another pair of contacts connected to another terminal of said manually operated switch and to the solenoid of said solenoid operated switching device, said energizing circuits being controlled and alternatively closed by the manually operated switch selectively contacting one of said terminals, the energization of said locking device unlocking the switching device for return into its inoperative position.

2. A safety device controlling the connection between a source of current and the depending current excited elements of a system, said system including a manually operated control switch, said safety device comprising a solenoid operated switching device including a solenoid, a plunger provided with a solenoid core operated by said solenoid, and with a plunger rod in a direction opposed to the direction of movement of the core upon energization of the solenoid, a first pair of contacts connected with said source of current and with the elements of the system and a solenoid operated locking device respectively, a movable contact carried and operated by said plunger rod connecting said first pair of contacts when the solenoid is energized, a second pair of contacts connected to ground and to said solenoid operated locking device and said elements of said system respectively, means continuously urging said movable contact to engage said second pair of contacts, a solenoid operated locking device having a solenoid and being arranged adjacent to the switching device and provided with a plunger rod substantially at right angles to the plunger rod of the switching device and a movable contact carried and operated by said plunger rod of the locking device, and with spring means for moving the plunger rod of the locking device in one direction, the said locking device being further provided with a locking plate attached to said plunger rod of the locking device and adapted to be moved into the path of the plunger rod of the switching device for locking the same into its operative position, energizing circuits for each of said solenoid operated devices interlocking the operation of said devices so as to automatically lock when brought into operative position, said energizing circuits including one pair of contacts connected to said solenoid operated switching device and to one terminal of said manually operated switch, respectively, another pair of contacts connected to another terminal of said manually operated switch and to the solenoid of said solenoid operated switch device, said energizing circuits being controlled and alternatively closed by the manually operated switch selectively contacting one of said terminals, the energization of said locking device unlocking the switching device for return into its inoperative position, a first plate having an aperture therethrough, said plunger rod selectively passing through said plate when said solenoid of the solenoid operated switching device is not excited, a second plate carried by said plunger rod of the solenoid actuated locking device, said second plate being so positioned as to cover the aperture in the first plate when said solenoid of the solenoid actuated locking device is not actuated to thus prevent the plunger rod of said solenoid actuated switching device from passing into said aperture, the current consumption of the safety device being thus limited to the period of change of said movable contacts.

VERNON H. HAY. WYATT J. ARM'FIELD.

REFERENCES GETED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,176,202 Cheney Mar. 21, 1916 1,564,815 Ballance Dec. 8, 1925 2,221,604 Peterson Nov. 12, 1940 2,453,267 Rossmann Nov. 9, 194% 

